Dear Dhyaa, I would recommend that you go through the manual and read about the Interface input as your question seems related to it. I guess you can model it by assigning bentonite properties to the interface, or by simply assigning a proper value for…

Dear Mohamad, It depends on which side the interface is pointed at. In your model, I assume you refer to the one between the black material and the yellow. The activated interface is on the yellow side, so it will take the properties of that soil…